The Catalan club said that the Brazilian international would be out of action for between four and six weeks depending on how well he responded to treatment.

The injury will mean that Ronaldinho, who joined Barcelona from Paris St Germain in a deal worth up to 30 million euros ($34.44 million) at the start of the season, will almost certainly miss the clash against arch-rivals Real Madrid at the Nou Camp on December 6.

The 23-year-old World Cup winner was injured during the club's 2-1 win over Real Betis on Sunday, a victory that pushed Barcelona up to fourth place in the table.

In Rio de Janeiro, the Brazilian Football Confederation (CBF) said Barcelona had sent them a medical report and the player would not be required to report to the squad which starts training in the mountain retreat of Teresopolis on Tuesday.

The CBF said that Santos midfielder Elano had been called up in Ronaldinho's place.

Brazil, who top the South American World Cup qualifying group with a maximum six points from two games, are away to Peru in Lima on November 16 and at home to Uruguay in Curitiba three days later.

Brazil are also without Real Madrid left-back Roberto Carlos, who tore a muscle in his left leg during the Champions League match away to Partizan Belgrade last week.